The invention relates generally to systems for mounting a device onto another structure and, more particularly, to such systems which isolate the device from the structure so that vibration, torque and other motion-induced forces produced by the device do not adversely affect the structure and/or other subsystems and components mounted on the structure or proximal thereto. Such systems are particularly useful in space based environments in which many subsystems and components thereof are particularly sensitive to shock and vibration.
A mounting system for mounting a centrifuge onto an interior structure of a manned spacecraft is typically required to be stiff enough to resist applied torques due to spin-up and spin-down, aerodynamics, angular momentum (gyroscopic precession) and interaction by spacecraft crew personnel, while simultaneously providing a very soft platform for isolating the centrifuge from the spacecraft microgravity environment. Meeting these two conflicting requirements often resulted in a mounting system which was simply a compromise of both these requirements or which was very complex and/or expensive. In addition, since the space available in spacecraft to place the mounting system and centrifuge is typically limited, the mounting system is required to be compact. Moreover, another requirement of such a mounting system is that it eliminate stiction, i.e., resistance to start of motion. Stiction typically reduces the effectiveness of conventional isolation systems and introduces undesired noise and other disturbances into the spacecraft environment.
Many prior art mounting systems have been developed which provide a desired degree of shock and vibration isolation of a device such as a motor, centrifuge, gyroscope or other vibration or torque producing device. Some of these prior art designs, such the magnetic bearing and air bearing systems provide a very high degree of isolation but do so at a very high cost. In addition, such systems are not only very complex but, they also require an inordinate amount of energy for their proper operation. In addition, such systems do not provide the linear and angular stiffness which is required for many devices or applications.
Some prior art active systems provide a very high degree of isolation of devices. One of these types of active systems is a magnetic suspension system. The magnetic suspension system utilizes stator structures and an armature which is isolated from disturbance forces of the stators. However, such active systems have significant energy consumption. In addition, such active systems generally require a controller with associated software thereby resulting in a system which is inordinately complex and expensive to use, maintain and purchase.
Other more conventional passive isolation systems such as shock mount systems provide a certain degree of isolation of such devices from the surrounding environment. Many such systems utilize elastomeric mounting structures for damping purposes. However, an inherent disadvantage of such elastomeric mounting structures is that they may allow a degree of rotational movement which is undesirable for many applications. Elastomeric mounting structures may also introduce nonlinearity of the spring constant as a function of deflection i.e., stiffness may increase as the stroke or deflection increases, which increases the complexity of the design. Elastomeric mounts also generally inherently provide damping which adds complexity to the system design over systems that have independently operating spring and damping elements. The subject invention resolves these issues in that it: 1) provides the correct combination of linear and angular stiffness that allows the desired translational motion while preventing rotational motion, 2) provides a highly linear spring constant over the relatively large (approximately 0.5 inch) required defection range, and 3) provides independent control of stiffness and damping parameters.
A vibration isolation mounting system is thus needed which can protect the surrounding environment from vibration, torque and other motion-related forces produced by the device or subsystem which it holds. Such a system is also needed which is compact and provides a desired combination of linear and angular stiffness.